Functional and structural basis of E. coli enolase inhibition by SF2312: A mimic of the carbanion intermediate

• Main Authors: Krucinska, Jolanta, Lombardo, Michael N., Erlandsen, Heidi, Hazeen, Akram, Duay, Searle S., Pattis, Jason G., Robinson, Victoria L., May, Eric R., Wright, Dennis L.
• Format: text
• Published: Animo Repository 2019
• Subjects: Escherichia coli; Enolase; Metabolites; Carbanions; Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/11299
• Institution: De La Salle University

Many years ago, the natural secondary metabolite SF2312, produced by the actinomycete Micromonospora, was reported to display broad spectrum antibacterial properties against both Gram-positive and Gram-negative bacteria. Recent studies have revealed that SF2312, a natural phosphonic acid, functions as a potent inhibitor of human enolase. The mechanism of SF2312 inhibition of bacterial enolase and its role in bacterial growth and reproduction, however, have remained elusive. In this work, we detail a structural analysis of E. coli enolase bound to both SF2312 and its oxidized imide-form. Our studies support a model in which SF2312 acts as an analog of a high energy intermediate formed during the catalytic process. Biochemical, biophysical, computational and kinetic characterization of these compounds confirm that altering features characteristic of a putative carbanion (enolate) intermediate significantly reduces the potency of enzyme inhibition. When SF2312 is combined with fosfomycin in the presence of glucose-6 phosphate, significant synergy is observed. This suggests the two agents could be used as a potent combination, targeting distinct cellular mechanism for the treatment of bacterial infections. Together, our studies rationalize the structure-activity relationships for these phosphonates and validate enolase as a promising target for antibiotic discovery.